I have a project with this structure:
/path/to/my/project
├── CMakeLists.txt
├── internal-libs
│ ├── internal-lib1
├── libs
│ ├── lib1
│ ├── lib2
lib1 is a static library.
lib2 is a static library.
internal-lib1 is a static library.
lib2 links statically to lib2 and internal-lib1. lib1 and lib2 are going to be exported but internal-lib1 will be left behind. For the linkage, I have:
target_link_libraries(lib2 PRIVATE internal-lib1)
target_link_libraries(lib2 PRIVATE lib1)
My understanding is that because I am linking statically and privately, All the information about internal-lib1 would be contained in lib2 and that I won't have to export internal-lib1 to the outside world.
However, when I try to use it in a client program, I get the error:
/usr/bin/ld cannot find -llib-internal1
collect2: error: ld returned 1 exit status
in my generated Export config file, I have:
# Create imported target lib2
add_library(lib2 STATIC IMPORTED)
set_target_properties(lib2 PROPERTIES
INTERFACE_LINK_LIBRARIES "$<LINK_ONLY:lib1>;**$<LINK_ONLY:internal-lib1>**"
)
# Create imported target lib1
add_library(lib1 STATIC IMPORTED)
Am I misunderstanding the static linking or is there something wrong with my setup? I am using cmake 3.2.2. All my target includes are PRIVATE. I don't understand why INTERFACE_LINK_LIBRARIES is populated with entries and what LINK_ONLY means.
p.s. Actually lib1 and lib2 are supposed to be shared libraries but I can't even get the static version working so for simplicity here I am describing the static case for the exportable libraries.